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Geoff Wootton
Grand Master
Username: dounraey

Post Number: 1973
Registered: 5-2012
Posted on Monday, 18 June, 2018 - 02:26 am:   Edit PostDelete PostView Post/Check IP

The air con on my 74 SY1 (SRX18501) blows ice cold air however when I close the central air conditioning flap to redirect the air through the two circular outlet ducts either side of the fascia, I get a mixture of A/C cold air and ram effect ambient air. i.e. the air is only chilled. Is this normal operation for the air con on a series 1 car. I would have assumed manually closing the central flap would have internally blocked off the ram air from outside to allow ice cold air to be blown through the two circular ducts.

I'm trying to figure out if there is a fault on my car. The handbook is ambiguous about this, saying only "cold air can be supplied through these ducts"
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Jeff McCarthy
Grand Master
Username: jefmac2003

Post Number: 518
Registered: 5-2007
Posted on Monday, 18 June, 2018 - 06:47 am:   Edit PostDelete PostView Post/Check IP

Geoff the usual culprit is the recirculation flaps. These are controlled by small electric actuators which get stuck. Some are accessible under small plastic cages via the front footwell. Others less so. I think there are instructions in the manuals.

The air through the vents should be ice cold, not ambient temperature.
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Geoff Wootton
Grand Master
Username: dounraey

Post Number: 1974
Registered: 5-2012
Posted on Monday, 18 June, 2018 - 07:59 am:   Edit PostDelete PostView Post/Check IP

Jeff

Thanks for that. I know your car is also a 74 so that's confirmed it. I thought the setup on my car was strange. I'll check out all the actuators as you have suggested.

Geoff
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Alan Dibley
Prolific User
Username: alsdibley

Post Number: 151
Registered: 10-2009
Posted on Monday, 18 June, 2018 - 05:44 pm:   Edit PostDelete PostView Post/Check IP

To check most of the actuators:-

1) Find a quiet environment.
2) Open the bonnet/hood.
3) Turn on the ignition.
4) Move any of the A/C switches in any direction (in/out or right/left) by one notch.
5) Listen for a whirring noise from the A/C area. There should be a short whirring noise when a switch is moved in one direction and a long noise (a few seconds) when moved in the other direction. The motors turn in only one direction so it takes a long time for the control to get right round the circle to the next position back.

No whirring means an actuator needs attention. Which one? Aaah, there's a question. Read the manual.

Some switches produce action from two actuators so the check is not perfect.

Alan D.
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gordon le feuvre
Prolific User
Username: triumph

Post Number: 251
Registered: 7-2012
Posted on Wednesday, 20 June, 2018 - 07:53 pm:   Edit PostDelete PostView Post/Check IP

GEOFF, HAVE SOME UPDATED INFO, WILL POST IN NEXT 24HRS
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Geoff Wootton
Grand Master
Username: dounraey

Post Number: 1975
Registered: 5-2012
Posted on Wednesday, 20 June, 2018 - 11:39 pm:   Edit PostDelete PostView Post/Check IP

Alan - Thanks for the additional information.

Gordon - I look forward to the updated info.

I have not yet started work on this problem other than do some additional tests. The manual says there is a flap for each circular fascia duct so I was hoping one duct would be blowing cold and the other warm. Not the case - both are warm. It's quite possible both servos are jammed, or more likely, my analysis is wrong due to my total lack of knowledge of the ventilation system. That will change in a couple of weeks time when I have time to sort this (interesting) problem.
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Steve Janosik
New User
Username: catullus

Post Number: 7
Registered: 8-2017
Posted on Thursday, 21 June, 2018 - 12:06 am:   Edit PostDelete PostView Post/Check IP

Have you checked the coolant servo that regulates hot water to the heater core? It is in the vicinity of the hydraulic reservoir.
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Geoff Wootton
Grand Master
Username: dounraey

Post Number: 1976
Registered: 5-2012
Posted on Thursday, 21 June, 2018 - 12:37 am:   Edit PostDelete PostView Post/Check IP

Hi Steve

Yes, it's fine. The heater core is definitely off. I've checked it.

The air con works great through the central vent but not through the circular fascia vents, where I get a mixture of ice cold air and ambient temperature ram air.
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gordon le feuvre
Prolific User
Username: triumph

Post Number: 252
Registered: 7-2012
Posted on Thursday, 21 June, 2018 - 01:28 am:   Edit PostDelete PostView Post/Check IP


When "upper" acu switch is vertical or clockwise the airflow to bulls eyes is ambient air. When "upper" switch turned anticlock one position, the change-over actuator( situated behing top roll/facia) will open the flap to allow 'fridged air that has come through the evaporator to go up to ducting where bulls eyes are. At the same time, this flap closes off the ambient air flow to bulls eyes. If you turn on ign. and open bulls eye by shining torch into aperture this operation can be observed. What happened, giving your symtoms is that the flap pivots on small plastic buses that fall apart with age allowing flap to twist when operating and not fully close off the flow of ambient air direct to bulls eyes. When the changeover flap operating correctly ALL air being forced into heater box by blowers should be directed through evaporator ( see my not very good drawing) The bad news is that this flap is behind heater box cover under bonnet, which requires blowers/ducting/blower bases/main heater box cover to be removed for access! If ign. is turned off halfway through actuator cycle, by putting screwdriver into bullseye "hole", you might get to feel how loose flap is.
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Geoff Wootton
Grand Master
Username: dounraey

Post Number: 1977
Registered: 5-2012
Posted on Thursday, 21 June, 2018 - 03:15 am:   Edit PostDelete PostView Post/Check IP

Gordon

Brilliant. That is so helpful. Thank you.

This also explains why I get warm air through both bulls eyes.

The good news is I do not have to take the car off the road to carry out the repair. I've had the blowers and ducts off before and have a couple of plates to cover the holes between the engine and passenger compartments. So this is a big job I can carry out at leisure.

Should have it done just in time for the high summer mega temperatures.

Geoff
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Geoff Wootton
Grand Master
Username: dounraey

Post Number: 1978
Registered: 5-2012
Posted on Thursday, 21 June, 2018 - 03:56 am:   Edit PostDelete PostView Post/Check IP

Just to confirm Gordon's diagnosis, here's a pic looking down the bullseye with the vent open. You can see the flap at the back with the tatty orange colored foam rubber. I can hear the servo running as I switch the upper heating knob however, as Gordon predicted, the flap doesn't move. I assume it should rise upwards to cover the duct just behind it.

I notice the right hand bulls eye is the same. I'm wondering if there are two flaps on my car on the same spindle. I guess all will become obvious when I get in there.

be
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gordon le feuvre
Prolific User
Username: triumph

Post Number: 253
Registered: 7-2012
Posted on Thursday, 21 June, 2018 - 08:08 am:   Edit PostDelete PostView Post/Check IP

Geoff, glad to help. Just one long flap. Attended original Shadow course covering TWO WEEKS at Hythe Rd in 1967, some of it stuck!
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Geoff Wootton
Grand Master
Username: dounraey

Post Number: 1979
Registered: 5-2012
Posted on Thursday, 21 June, 2018 - 09:13 am:   Edit PostDelete PostView Post/Check IP

Many thanks Gordon.

If anyone is interested I can post pics when I do this job.
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Jeff McCarthy
Grand Master
Username: jefmac2003

Post Number: 519
Registered: 5-2007
Posted on Thursday, 21 June, 2018 - 12:58 pm:   Edit PostDelete PostView Post/Check IP

Just so you know what you're looking for/at:

https://www.youtube.com/watch?v=fI7lbNJQq6k
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gordon le feuvre
Prolific User
Username: triumph

Post Number: 254
Registered: 7-2012
Posted on Saturday, 23 June, 2018 - 04:15 pm:   Edit PostDelete PostView Post/Check IP

Geoff, part no is UD11158 It is listed as grommet and there is one at each end flap listed at 2.66 each on Flying Spares site. Also available from dealer network. If you were changing all of them ,I think there are 4 for upper quantity/temp flap. 4 for lower quantity/temp flap, 2 for change over flap (as we have been dealing with) and 2 for each recirculation flaps located at each end of front footwells, At least you CAN see the recirc. flaps operating, These operate when FULL anti clock selected on upper knob.
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Geoff Wootton
Grand Master
Username: dounraey

Post Number: 1981
Registered: 5-2012
Posted on Wednesday, 27 June, 2018 - 04:43 am:   Edit PostDelete PostView Post/Check IP

Jeff and Gordon

Thanks for the additional info.

It looks like I should be able to make a start on this project this weekend.
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Mike Eames
Yet to post message
Username: mike

Post Number: 1
Registered: 1-2005
Posted on Thursday, 28 June, 2018 - 05:36 pm:   Edit PostDelete PostView Post/Check IP

Geoff, While all the above is true and helpful, it may be worth checking/replacing the diodes (located on the fuse board). The servo motors that control the various flaps can misbehave when these fail.
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gordon le feuvre
Prolific User
Username: triumph

Post Number: 255
Registered: 7-2012
Posted on Thursday, 28 June, 2018 - 06:22 pm:   Edit PostDelete PostView Post/Check IP

Mike, very true, but it will not give the symptoms of a mixture of ambient and 'fridged air. We discovered by accident that if the, I think bulls eye actuator diode misbehaved, hot air would come out of bulls eyes,some owners liked this to blow on their left hand whilst driving rhd cars in winter!

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